Clindamycin, 7(S)-chloro-7-deoxylincomycin, the preparation of which is described in U.S. Pat. No. 3,487,068 issued Dec. 30, 1969, is a potent antibacterial agent. Clindamycin is a derivative of the amino acid trans-L-4-n-propylhygrinic acid, attached to a sulfur-containing derivative of an octose.
Clindamycin and lincomycin bind exclusive to the 50 S subunit of bacterial ribosomes and suppress protein synthesis. Although clindamycin, erythromycin and chloramphenicol are not structurally related, they all act at this site, and the binding of one of these antibiotics to the ribosome may inhibit the reaction of the other. In general, clindamycin is similar to erythromycin in its activity in vitro against pneumococci, Strep. pyogenes, and viridans streptococci. Almost all such bacterial strains are inhibited by concentrations of 0.04 .mu.g/mL. It is also active against many strains of Staph. aureus but may not inhibit methicillin-resistant strains. Clindamycin is nearly completely absorbed following oral administration, and peak plasma concentrations of 2 to 3 .mu.g/mL are attained within 1 hour after the injestion of 150 mg. The presence of food in the stomach does not reduce absorption significantly. The half-life of the antibiotic is about 2.5 hours, and modest accumulation of drug is to be expected if it is given at 6 hour intervals. The phosphate ester of clindamycin which is given parenterally, is also rapidly hydrolyzed in vivo to the active parent compound. Following intramuscular injection, peak concentrations in plasma are not attained for 3 hours in adults and 1 hour in children. The recommended parenteral dosages provide peak plasma concentrations of 5 to 15 .mu.g/mL and effective antimicrobial activity for approximately 8 hours. Most of the drug is inactivated by metabolism to N-demethylclindamycin and clindamycin sulfoxide, which are excreted in the urine and bile. The half-life of clindamycin is lengthened only slightly in patients with markedly impaired renal function, and little adjustment of dosage is required for such individuals.